The ink layers for printing on printing devices are created according to the settings for light/dark ink splitting in the printer driver and the settings for black generation and spot color handling in the ICC color profiles that are used for color separation. Using such state-of-the art methods, it is not possible to take the real ink cost into account, especially when the inks are dynamically changing. The printing industry works with the assumption that the cost of printing inks is approximately equal but, for instance, in the ceramic industry it may happen that the black ink is twice as expensive compared with other inks, such as brown ink.
Within the CMY color space, a range of colors can be achieved by combining the three primary colors. This combination in its turn can be thought of as a hue component, which requires a maximum of two primary colors, and a grey component, which is a mixture of all three, in an appropriate quantity to give the required saturation. If the grey component is replaced by black ink, the same color is achieved by using two primaries and black. The act of substituting a quantity of black for the grey component is known as Grey Component Replacement (GCR). In GCR, the CMY values that add to grey all along the tone scale can be replaced with black ink.
Additionally, the splitting of light and dark inks is done without consideration of the location of the color to be printed in the color space and thus lead to an unnecessary high amount of light ink usage in dark areas where there is no advantage of using light inks instead of dark inks. The reason for that is the fact that conventional ICC profiling applications are unable to handle light and dark inks as separate colors.